Apparatus and method for reducing call set-up time for time-sensitive applications in a wireless network

ABSTRACT

For use in a wireless network, a base station that reduces the call set-up time for a time-sensitive application. The base station comprises a message controller for receiving an incoming control message that initiates the time-sensitive application in a mobile station. In lieu of a conventional page message, the message controller transmits a short data burst message to the mobile station to initiate the time-sensitive application. The short data burst message is transmitted in a forward control channel. The mobile station completes the set-up by transmitting back an L2 Acknowledgment message in lieu of a conventional page response message.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

The present invention is related to that disclosed in U.S. ProvisionalPatent No. 60/575,609, filed May 27, 2004, entitled “Technique To ReduceThe Call Set-Up Time For The Guaranteed Time Sensitive Applications”.U.S. Provisional Patent No. 60/575,609 is assigned to the assignee ofthe present application. The subject matter disclosed in U.S.Provisional Patent No. 60/575,609 is hereby incorporated by referenceinto the present disclosure as if fully set forth herein. The presentapplication hereby claims priority under 35 U.S.C. §119(e) to U.S.Provisional Patent No. 60/575,609.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to wireless networks and, morespecifically, to a mechanism for reducing the call set-up time forguaranteed time-sensitive applications in a wireless network.

BACKGROUND OF THE INVENTION

The use of cellular telephones and wireless networks has becomeincreasingly widespread. As the use of cellular telephones hasincreased, the number and quality of additional features made availablewith the cellular telephones has also increased. For example, manymobile stations (i.e., cellular telephones) now provide chatapplications, such as a Push-To-Talk service, for example. Push-to-Talk(PT) service is a “walkie-talkie” type of feature that allows a mobilestation user to communicate with another mobile station user (or users)by pushing a single button on the cell phone.

Chat applications, such as Push-To-Talk (PTT) service, are useful forsituations in which a user wants or needs to communicate with the sameperson or group of people repeatedly but not continuously. For example,a group of people at a mall may desire to keep in touch with each otherafter they split up to shop separately. Using Push-To-Talk, one personmay quickly contact another person or other people without having tomake a conventional cellular phone call.

The parties involved must first establish a PTT service between theirrespective phones. The wireless network is then aware of the presence ofeach mobile station (e.g., cell phone) involved in the PTT service,although no traffic channels are set up. The mobile stations initiallycommunicate with the base stations of the wireless network using onlyoverhead control channels to establish the PTT service. Once the PTTservice is established, the call originator does not have to dial thenumber of the called party in order to communicate. The call originatoronly needs to press a button, wait for a beep (or a similar indicator),and then speak. Advantageously, many service providers do not chargethese conversations against the users' allotted usage minutes for thecellular telephones.

Many conventional wireless network, such as code division multipleaccess (CDMA) systems, are designed under a switched voice model.Therefore, a set-up time of several seconds is deemed acceptable to userexpectations. However, as CDMA and other conventional wireless protocolsare increasingly used for time-sensitive services, faster call set-uptimes are required. As CDMA and other protocols have evolved to servepacket data needs, the paging procedures of those protocols have changedonly slightly. As a result, the paging delays experienced in CDMA2000packet data sessions are detrimental to user latency and networkefficiency.

Currently, in CDMA2000 systems, the time set-up for real-time servicessuch as chat includes the delays associated with the call originatorsending the request to the base station, the base station sending therequest to the chat server, the target base station paging the targetmobile station, and the target mobile station acknowledging receipt ofthe paging message. One of the largest delays in this string oftransactions is the time required for paging the target mobile stationand for the target mobile station to acknowledge with a page responsemessage. This delay alone may consume up to 500 milliseconds.

Therefore, there is a need in the art for improved wireless networksthat have reduce call set-up time for time-sensitive applications. Inparticular, there is a need for a CDMA2000 wireless network thatprovides reduce call set-up times for chat and Push-To-Talk services.

SUMMARY OF THE INVENTION

The present invention provides a technique for reducing the overall callset-up time for real-time or time-sensitive services by optimizing thepaging procedure at the target base station. The present inventionovercomes the shortcomings of the prior art by modifying and/oreliminating the Page message and the Page Response message. The latencyreduction achieve by the present invention may be anywhere from 500milliseconds to 1 second.

To address the above-discussed deficiencies of the prior art, it is aprimary object of the present invention to provide, for use in awireless network, a base station capable of reducing the call set-uptime for a time-sensitive application. According to an advantageousembodiment of the present invention, the base station comprises amessage controller capable of receiving an incoming control messageoperable to initiate the time-sensitive application in a first of theplurality of mobile stations, wherein the message controller transmits ashort data burst message to the first mobile station to initiate thetime-sensitive application in the first mobile station.

According to one embodiment of the present invention, the short databurst message is transmitted in a forward control channel of thewireless network.

According to another embodiment of the present invention, wherein thebase station further comprises a memory capable of storing mobilestation information associated with the first mobile station, the mobilestation information comprising at least one of operating parameterinformation and location information associated with the first mobilestation.

According to still another embodiment of the present invention, themessage controller is further capable of determining if the mobilestation information associated with the first mobile station is storedin the memory.

According to yet another embodiment of the present invention, themessage controller, in response to a determination that the mobilestation information associated with the first mobile station is storedin the memory, transmits only the short data burst message to the firstmobile station in order to initiate the time-sensitive application inthe first mobile station.

According to a further embodiment of the present invention, the messagecontroller is capable of receiving from the first mobile station a Layer2 Acknowledgment message responding to the short data burst message.

According to a still further embodiment of the present invention, themessage controller, in response to a determination that the mobilestation information associated with the first mobile station is notstored in the memory, transmits to the first mobile station the shortdata burst message and a modified Page message appended to the shortdata burst message in order to initiate the time-sensitive applicationin the first mobile station, wherein the modified Page message requestsat least a portion of the mobile station information from the firstmobile station.

According to a yet further embodiment of the present invention, themessage controller is capable of receiving from the first mobile stationa Layer 2 Acknowledgment message and a Page Response message appended tothe Layer 2 Acknowledgment message, wherein the Page Response messagecomprises the requested at least a portion of the mobile stationinformation.

Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, itmay be advantageous to set forth definitions of certain words andphrases used throughout this patent document: the terms “include” and“comprise,” as well as derivatives thereof, mean inclusion withoutlimitation; the term “or,” is inclusive, meaning and/or; the phrases“associated with” and “associated therewith,” as well as derivativesthereof, may mean to include, be included within, interconnect with,contain, be contained within, connect to or with, couple to or with, becommunicable with, cooperate with, interleave, juxtapose, be proximateto, be bound to or with, have, have a property of, or the like; and theterm “controller” means any device, system or part thereof that controlsat least one operation, such a device may be implemented in hardware,firmware or software, or some combination of at least two of the same.It should be noted that the functionality associated with any particularcontroller may be centralized or distributed, whether locally orremotely. Definitions for certain words and phrases are providedthroughout this patent document, those of ordinary skill in the artshould understand that in many, if not most instances, such definitionsapply to prior, as well as future uses of such defined words andphrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an exemplary wireless network that reduces the callset-up time for guaranteed time-sensitive applications according to theprinciples of the present invention;

FIG. 2 illustrates an exemplary base station that reduces the callset-up time for guaranteed time-sensitive applications according to theprinciples of the present invention;

FIG. 3 illustrates an exemplary mobile station that reduces the callset-up time for guaranteed time-sensitive applications according to theprinciples of the present invention;

FIG. 4 is a flow diagram illustrating a conventional call set-upoperation according to one embodiment of the prior art;

FIG. 5 is a flow diagram illustrating a call set-up operation accordingto a first embodiment of the present invention;

FIG. 6 is a flow diagram illustrating a call set-up operation accordingto a second embodiment of the present invention; and

FIG. 7 illustrates a modified Page message according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 through 7, discussed below, and the various embodiments used todescribe the principles of the present invention in this patent documentare by way of illustration only and should not be construed in any wayto limit the scope of the invention. Those skilled in the art willunderstand that the principles of the present invention may beimplemented in any suitably arranged wireless network.

FIG. 1 illustrates exemplary wireless network 100, which reduces thecall set-up time for time-sensitive applications according to theprinciples of the present invention. Wireless network 100 comprises aplurality of cell sites 121-123, each containing one of the basestations, DS 101, BS 102, or BS 103. Base stations 101-103 communicatewith a plurality of mobile stations (MS) 111-114 over code divisionmultiple access (CDMA) channels according to, for example, the IS-2000standard (i.e., CDMA2000). In an advantageous embodiment of the presentinvention, mobile stations 111-114 are capable of receiving data trafficand/or voice traffic on two or more CDMA channels simultaneously. Mobilestations 111-114 may be any suitable wireless devices (e.g.,conventional cell phones, PCS handsets, personal digital assistant (PDA)handsets, portable computers, telemetry devices) that are capable ofcommunicating with base stations 101-103 via wireless links.

The present invention is not limited to mobile devices. The presentinvention also encompasses other types of wireless access terminals,including fixed wireless terminals. For the sake of simplicity, onlymobile stations are shown and discussed hereafter. However, it should beunderstood that the use of the term “mobile station” in the claims andin the description below is intended to encompass both truly mobiledevices (e.g., cell phones, wireless lap tops) and stationary wirelessterminals (e.g., a machine monitor with wireless capability).

Dotted lines show the approximate boundaries of cell sites 121-123 inwhich base stations 101-103 are located. The cell sites are shownapproximately circular for the purposes of illustration and explanationonly. It should be clearly understood that the cell sites may have otherirregular shapes, depending on the cell configuration selected andnatural and man-made obstructions.

As is well known in the art, each of cell sites 121-123 is comprised ofa plurality of sectors, where a directional antenna coupled to the basestation illuminates each sector. The embodiment of FIG. 1 illustratesthe base station in the center of the cell. Alternate embodiments mayposition the directional antennas in corners of the sectors. The systemof the present invention is not limited to any particular cell siteconfiguration.

In one embodiment of the present invention, each of BS 101, BS 102 andBS 103 comprises a base station controller (BSC) and one or more basetransceiver subsystem(s) (BTS). Base station controllers and basetransceiver subsystems are well known to those skilled in the art. Abase station controller is a device that manages wireless communicationsresources, including the base transceiver subsystems, for specifiedcells within a wireless communications network. A base transceiversubsystem comprises the RF transceivers, antennas, and other electricalequipment located in each cell site. This equipment may include airconditioning units, heating units, electrical supplies, telephone lineinterfaces and RF transmitters and RF receivers. For the purpose ofsimplicity and clarity in explaining the operation of the presentinvention, the base transceiver subsystems in each of cells 121, 122 and123 and the base station controller associated with each basetransceiver subsystem are collectively represented by BS 101, BS 102 andBS 103, respectively.

BS 101, BS 102 and BS 103 transfer voice and data signals between eachother and the public switched telephone network (PSTN) (not shown) viacommunication line 131 and mobile switching center (MSC) 140. ES 101, BS102 and BS 103 also transfer data signals, such as packet data, with theInternet (not shown) via communication line 131 and packet data servernode (PDSN) 150. Packet control function (PCF) unit 190 controls theflow of data packets between base stations 101-103 and PDSN 150. PCFunit 190 may be implemented as part of PDSN 150, as part of MSC 140, oras a stand-alone device that communicates with PDSN 150, as shown inFIG. 1. Line 131 also provides the connection path for control signalstransmitted between MSC 140 and BS 101, BS 102 and BS 103 that establishconnections for voice and data circuits between MSC 140 and BS 101, BS102 and BS 103.

Communication line 131 may be any suitable connection means, including aT1 line, a T3 line, a fiber optic link, a network packet data backboneconnection, or any other type of data connection. Line 131 links eachvocoder in the BSC with switch elements in MSC 140. The connections online 131 may transmit analog voice signals or digital voice signals inpulse code modulated (PCM) format, Internet Protocol (IP) format,asynchronous transfer mode (ATM) format, or the like.

MSC 140 is a switching device that provides services and coordinationbetween the subscribers in a wireless network and external networks,such as the PSTN or Internet. MSC 140 is well known to those skilled inthe art. In some embodiments of the present invention, communicationsline 131 may be several different data links where each data linkcouples one of BS 101, BS 102, or BS 103 to MSC 140.

In the exemplary wireless network 100, MS 111 is located in cell site121 and is in communication with BS 101. MS 113 is located in cell site122 and is in communication with BS 102. MS 114 is located in cell site123 and is in communication with BS 103. MS 112 is also located close tothe edge of cell site 123 and is moving in the direction of cell site123, as indicated by the direction arrow proximate MS 112. At somepoint, as MS 112 moves into cell site 123 and out of cell site 121, ahand-off will occur.

According to an advantageous embodiment of the present invention,wireless network 100 provides certain time-sensitive services to mobilestations 111-114. In particular, wireless network 100 is capable ofproviding a chat service, such as Push-To-Talk (PTT) service, between anoriginating mobile station and a target mobile station. The PTT servicerequires fast set-up times in order to provide the chat service in areal-time manner. The present invention provides a technique forreducing the overall call set-up time for real-time/time-sensitiveservices by optimizing the paging procedure at the target base station.

FIG. 2 illustrates in greater detail exemplary base station 101, whichreduce the call set-up time for guaranteed time-sensitive applicationsaccording to the principles of the present invention. Base stations 102and 103 are identical to base station 101 and are not describedseparately. Base station 101 comprises base station controller (BSC) 210and base transceiver station (BTS) 220. Base station controllers andbase transceiver stations were described previously in connection withFIG. 1. ESC 210 manages the resources in cell site 121, including BTS220. BTS 120 comprises BTS controller 225, channel controller 235 (whichcontains representative channel element 240), transceiver interface (IF)245, RF transceiver 250, antenna array 255, control channel (CC) messagecontroller 260, and mobile station (MS) information database 265.

BTS controller 225 comprises processing circuitry and memory capable ofexecuting an operating program that controls the overall operation ofBTS 220 and communicates with BSC 210. Under normal conditions, BTScontroller 225 directs the operation of channel controller 235, whichcontains a number of channel elements, including channel element 240,that perform bi-directional communications in the forward channel andthe reverse channel. A “forward” channel refers to outbound signals fromthe base station to the mobile station and a “reverse” channel refers toinbound signals from the mobile station to the base station. TransceiverIF 245 transfers the bi-directional channel signals between channelcontroller 240 and RF transceiver 250.

Antenna array 255 transmits forward channel signals received from RFtransceiver 250 to mobile stations in the coverage area of BS 101.Antenna array 255 also sends to RF transceiver 250 reverse channelsignals received from mobile stations in the coverage area of BS 101. Ina preferred embodiment of the present invention, antenna array 255 ismulti-sector antenna, such as a three-sector antenna in which eachantenna sector is responsible for transmitting and receiving in a 120°arc of coverage area. Additionally, RF transceiver 250 may contain anantenna selection unit to select among different antennas in antennaarray 255 during both transmit and receive operations.

Control channel (CC) message controller 260 is responsible forcommunicating with mobile stations in the common control channels andfor setting up call sessions, including Push-To-Talk sessions, betweenmobile stations according to the principles of the present invention. Inan exemplary embodiment of the present invention, control channelmessage controller 260 may be implemented as one of the functions of BTScontroller 225. However, for the purposes of clarity and simplicity inexplaining the operation of the present invention, control channelmessage controller 260 is shown in FIG. 2 as a separate unit from BTScontroller 225.

Mobile station (MS) information database 265 stores ID and parameterinformation about mobile stations that are communicating with basestation 101. The fact that base station 101 stores mobile stationparameters and other information enables the present invention toeliminate the paging mechanism, especially the page response message, asdescribed below in greater detail.

FIG. 3 illustrates in greater detail exemplary mobile station 111, whichreduces the call set-up time for guaranteed time-sensitive applicationsaccording to the principles of the present invention. Mobile stations112-114 are identical to mobile station 111 and are not describedseparately. Wireless mobile station 111 comprises antenna 305, radiofrequency (RF) transceiver 310, transmit (TX) processing circuitry 315,microphone 320, and receive (RX) processing circuitry 325. MS 111 alsocomprises speaker 330, main processor 340, input/output (I/O) interface(IF) 345, keypad 350, display 355, and memory 360. Memory 360 furthercomprises basic operating system (OS) program 361 and control channel(CC) message controller application 262.

Radio frequency (RF) transceiver 310 receives from antenna 305 anincoming RF signal transmitted by a base station of wireless network100. Radio frequency (RF) transceiver 310 down-converts the incoming RFsignal to produce an intermediate frequency (IF) or a baseband signal.The IF or baseband signal is sent to receiver (RX) processing circuitry325 that produces a processed baseband signal by filtering, decoding,and/or digitizing the baseband or IF signal. Receiver (RX) processingcircuitry 325 transmits the processed baseband signal to speaker 330(i.e., voice data) or to main processor 340 for further processing(e.g., web browsing).

Transmitter (TX) processing circuitry 315 receives analog or digitalvoice data from microphone 320 or other outgoing baseband data (e.g.,web data, e-mail, interactive video game data) from main processor 340.Transmitter (TX) processing circuitry 315 encodes, multiplexes, and/ordigitizes the outgoing baseband data to produce a processed baseband orIF signal. Radio frequency (RF) transceiver 310 receives the outgoingprocessed baseband or IF signal from transmitter (TX) processingcircuitry 315. Radio frequency (RF) transceiver 310 up-converts thebaseband or IF signal to a radio frequency (RF) signal that istransmitted via antenna 305.

In an advantageous embodiment of the present invention, main processor340 is a microprocessor or microcontroller. Memory 360 is coupled tomain processor 340. According to an advantageous embodiment of thepresent invention, part of memory 360 comprises a random access memory(RAM) and another part of memory 360 comprises a Flash memory, whichacts as a read-only memory (ROM).

Main processor 340 executes basic operating system (OS) program 361stored in memory 360 in order to control the overall operation ofwireless mobile station 111. In one such operation, main processor 340controls the reception of forward channel signals and the transmissionof reverse channel signals by radio frequency (RF) transceiver 310,receiver (RX) processing circuitry 325, and transmitter (TX) processingcircuitry 315, in accordance with well-known principles.

Main processor 340 also executes control channel (CC) message controllerprogram 362. Control channel message controller program 362 isresponsible for communicating with base station in the common controlchannels and for setting up a call session, including a Push-To-Talksession, with another mobile station via at least one base stationaccording to the principles of the present invention. In an exemplaryembodiment of the present invention, control channel message controllerprogram 362 may be implemented as one of the functions of basicoperating system program 361. However, for the purposes of clarity andsimplicity in explaining the operation of the present invention, controlchannel message controller program 362 is shown in FIG. 3 as a separateentity from basic operating system program 361.

Main processor 340 is capable of executing other processes and programsresident in memory 360. Main processor 340 can move data into or out ofmemory 360, as required by an executing process. Main processor 340 isalso coupled to I/O interface 345. I/O interface 345 provides mobilestation 111 with the ability to connect to other devices such as laptopcomputers and handheld computers. I/O interface 345 is the communicationpath between these accessories and main controller 340.

Main processor 340 is also coupled to keypad 350 and display unit 355.The operator of mobile station 111 uses keypad 350 to enter data intomobile station 111. Display 355 may be a liquid crystal display capableof rendering text and/or at least limited graphics from web sites.Alternate embodiments may use other types of displays.

FIG. 4 depicts flow diagram 400, which illustrates a conventional callset-up operation according to an exemplary embodiment of the prior art.In FIG. 4, it is assumed that mobile station (MS) 111 has alreadyaccessed base station (ES) 101 and mobile station (MS) 113 has alreadyaccessed base station (BS) 102. It is further assumed that the operatorof MS 111 initiates (or originates) a chat service (i.e., PTT) to MS113. Chat server 490 provides Push-to-Talk (PTT) service, or a similarservice, to mobile stations in wireless network 100. Chat server 490 maybe part of wireless network 100. Alternatively, wireless network 100 mayaccess chat server 490 via the Internet.

A PTT session is initiated when originating mobile station 111 transmitsshort data burst (SDB) message 401 in a reverse enhanced access channel(R-EACH) to originating base station (ES) 101. In response, BS 101transmits Acknowledgment Order message 402 in a forward common controlchannel (F-CCCH) to BS 111. BS 101 also transmits Call message 403 tochat server 490. Call message 403 contains information identifying boththe originating device (MS 111) and the target device (MS 113) to chatserver 490.

In response to Call message 402, chat server 490 transmits CallAcknowledgment message 404 back to BS 101. BS 101 then transmits CallAcknowledgment message 405 to MS 111, using, for example, a short databurst (SDB) message in a common control channel (CCCH). Finally, MS 111transmits Acknowledgment Order 406 a reverse enhanced access channel(R-EACH) to originating BS 101.

In response to Call message 415, chat server 490 also transmits Announcemessage 407 to target base station (BS) 102. BS 102 then begins settingup a call session with target MS 113. BS 102 transmits general Pagemessage 408 to MS 113. MS 113 responds by transmitting Page Responsemessage 409 back to BS 102. BS 102 then sends Announce message 410 as ashort data burst (SDB) message in a forward common control channel(F-CCCH). Finally, in response to Announce message 410, MS 113 transmitsAnnounce Acknowledgment message 411 as a short data burst (SDB) messagein a reverse enhanced access channel (R-EACH).

However, from the time that MS 113 receives general Page message 408 tothe time that BS 102 receives Announce Acknowledgment message 411, theremay be at least one second of latency. The present invention reducesthis latency by 500 milliseconds or more by eliminating some of thepaging operations that occur between target mobile station 113 andtarget base station 102.

One of the purposes of Page message 408 is to locate target mobilestation 113. Locating MS 113 is done by transmitting Page message 408 totarget MS 113 and MS 113 then transmitting Page Response message 409.

The present invention eliminates this by directly sending a short databurst message to target mobile station 113, rather than Page message408. Then, target MS 113 acknowledges the SDB message by sending a Layer2 (L2) Acknowledgment message. Target BS 102 may send a modified Pagemessage to target MS 113. Target MS 113 may acknowledge the Page messageby transmitting a Page Response message appended to (i.e., piggybackedonto) a Layer 2 Acknowledgement (L2 Ack) message or by transmitting onlythe L2 Acknowledgment message (if only the SDB message was sent). Thepresent invention may be implemented by appropriate modification of thecall stack software in control channel message controller 260 in BS 101,BS 102, and through BS 103 and by modifying control channel messagecontroller program 362 in MS 111-MS 114.

FIG. 5 depicts flow diagram 500, which illustrates a call set-upoperation according to a first embodiment of the present invention. InFIG. 5, messages 401-407 are exchanged as in the prior art embodimentdescribed in FIG. 4. However, messages 408-411 are eliminated andreplaced by messages 501 and 502. As is shown, BS 102 sends short databurst (SDB) message directly 501 to MS 113, rather than sending a Pagemessage and waiting for a Page Response message. Target MS 113 thenresponds to SDB message 501 by sending Layer 2 (L2) Acknowledgmentmessage 502.

If the location and parameters (e.g., slot cycle index, SCM, channelcapability information, etc.) of MS 113, which are normally conveyed inthe Page Response message (PRM), are stored in MS information database265 in BS 102, then BS 102 can directly send SDB message 502 in the idlestate. Since the information MS 113 would normally send in the PRM isalready known to BS 102, it is not necessary to transmit the PRM. MS 113simply acknowledges SDB message 501 with L2 Acknowledgment message 502.Thus, the time required for the call set-up procedure is greatlyreduced.

The above-described technique assumes that target base station 102stores the necessary information regarding the parameters for MS 113.This enables the paging mechanism, especially the Page Response message,to be eliminated. The above-described technique also assumes that targetbase station 102 knows the whereabouts of target mobile station 113. InRelease D of the CDMA2000 standard, a base station is capable oftracking a mobile station with techniques such as radio environmentreporting (RER) and tracking zone (TKZ) mechanism. As a result, targetBS 102 can locate target MS 113 by triggering either of thesetechniques, or some other well-known location determination technique.

FIG. 6 depicts flow diagram 600, which illustrates a call set-upoperation according to a second embodiment of the present invention. Inthe embodiment shown in FIG. 6, it is assumed that BS 102 does not knowthe parameter information for MS 113. In FIG. 6, messages 401-407 areexchanged as in the prior art embodiment described in FIG. 4. However,messages 408-411 are eliminated and replaced by messages 601 and 602. Asis shown, BS 102 sends short data burst (SDE) message 601, which mayinclude a modified Page message, to MS 113.

Target MS 113 then responds to Page/SDB message 601 by sending Layer 2(L2) Acknowledgment message 602, which may have a Page Response message(PRM) appended (i.e., piggy-backed) to the L2 message. Mobile station113 acknowledges message 601 with only L2 Acknowledgment message 602, ifBS 102 sent only SDB message 601 without a modified Page message. If SDEmessage 601 included the modified Page message, then MS 113 replies witha modified Page message appended to SDE message 601.

Appending the modified Page message to SDE message 601 and appending thePage Response message to L2 Acknowledgment message 602 reduces the callsetup-time, as in FIG. 5. Since the extra transactions of sending SDBmessage 601 and L2 Acknowledgment message 602 are concatenated with thePage message and the Page Response message, there is an extra savings ofaround 200-500 milliseconds over the prior art embodiment shown in FIG.4.

FIG. 7 illustrates modified Page message 700 according to an exemplaryembodiment of the present invention. Modified Page message 700 shows thepacket data unit (PDU) format that is appended to short data burst (SDB)message 601. If ES 102 is not aware of all of the required parametersfor MS 113, BS 102 sends modified Page message 700 in order to obtaincertain required parameters. The length of each filed is given in bytes.Those skilled in the art will recognize that many of the fields inmodified Page message 700 are similar to equivalent fields inconventional Page message 408.

Although the present invention has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present invention encompasssuch changes and modifications as fall within the scope of the appendedclaims.

1-16. (canceled)
 17. For use in a wireless network capable ofcommunicating with mobile stations in a coverage area of the wirelessnetwork, a mobile station capable of reducing the call set-up time for atime-sensitive application, the mobile station comprising: a messagecontroller capable of receiving from a base station of said wirelessnetwork a short data burst message operable to initiate saidtime-sensitive application in said mobile station, wherein said messagecontroller, in response to receipt of said short data burst message,transmits a Layer 2 Acknowledgment message responding to said short databurst message.
 18. The mobile station as set forth in claim 17, whereinsaid short data burst message is received in a forward control channelof said wireless network.
 19. The mobile station as set forth in claim18, wherein said message controller is further capable of determining ifsaid short data burst message comprises a Page message requestingparameter information associated with said mobile station.
 20. Themobile station as set forth in claim 19, wherein said messagecontroller, in response to a determination that said short data burstmessage comprises a Page message requesting parameter informationassociated with said mobile station, is further capable of transmittingto said base station a Page Response message appended to said Layer 2Acknowledgment message, wherein said Page Response message comprisessaid requested parameter information.